Absorbable compositions and methods for their use in hemostasis

ABSTRACT

The present invention is direct to a body-absorbable, mechanically hemostatic composition comprising a solid poloxamer having an average molecular weight of about 7,000 g/mol to about 15,000 g/mol, a high molecular weight dextran, optionally a fatty acid salt, and water, and a method for mechanically controlling the bleeding of bone comprising applying an effective amount of the composition to the affected area.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 61/951,859, which was filed on Mar. 12, 2014, and whichis incorporated by reference in its entirety herein.

BACKGROUND OF THE INVENTION

The invention relates to an absorbable implantable composition andmethod of use for surgical control of osseous hemorrhage and improvementof healing of osseous defects.

Cancellous and cortical bone contains relatively vascular tissues thatbleed when their vasculature is disrupted. Thus, when bone is surgicallyincised or fractured traumatically, e.g., in open or compound fractures,there are at least two major issues which must be medically resolved.The first of these is the occurrence of osseous hemorrhage. When osseoushemorrhage ensues, it must be stopped or effectively controlled(hemostasis) to prevent adverse surgical consequences. The second issueis that of bone growth to promote healing (osteogenesis) of thetraumatized bone. Common procedures in which bone is surgically cutinclude open-heart surgery involving the splitting of the sternum,orthopedic and spinal surgery including hip implants, neurosurgeryinvolving spine or cranial incisions, amputations, trauma treatment, andmany other procedures.

At the present time, bone hemostasis is achieved by one or more of (i)manually impregnating the bleeding surface with commercially available,non-absorbable “bone wax” to achieve mechanical control of bleeding,(ii) applying one or more hemostatic agents or sealants such as oxidizedcellulose, microcrystalline collagen, human thrombin, and humanfibrinogen, to enhance coagulation at the bleeding site, and (iii)electrocautery. None of these techniques promotes osteogenesis to anysignificant extent. In addition to the unmet need for an effective,rapidly absorbable bone hemostatic material, there is also a surgicalneed for materials to fill bone defect voids and promote healing in suchcavities. A variety of paste-like materials, presently available to thesurgeon for this purpose, most commonly are based upon coarselypowdered, demineralized allogeneic bone, suspended in a suitable,biocompatible vehicle. These compositions are designed for inducingosteogenesis and healing in the defect but, because of theirconsistency, non-cohesiveness and other physical attributes of theircomposition, they do not reliably adhere to injured bone and are noteffective hemostatic agents.

There are two major bodies of prior art concerned with bone hemostasisand bone healing, respectively. As discussed below, only products basedupon plasticized non-absorbable waxes have generally been available tothe surgeon for bone hemostasis. The few alternatives, such as makeshiftdevices using oxidized cellulose and electrocautery (discussed below),are not satisfactory.

The first body of art is directed specifically to bone waxes which aremanually pressed into the pores of the bleeding bone surface, act as aneffective mechanical tamponade, and prevent blood from escaping.Presently available bone waxes consist of mixtures of non-absorbablecomponents such as bee's wax, paraffin, petrolatum, fatty esterplasticizers, and the like. These products must be warmed before use andbecome soft, kneadable and spreadable by the surgeon onto and into cutbone surfaces. Because available bone waxes are not absorbable andreside indefinitely where they are placed by the surgeon, they act aspermanent physical barriers that inhibit osteogenesis, therebypreventing or slowing bone healing. In addition, such a site acts as aperpetual postoperative nidus for infection. If such infection doesoccur, it is usually chronic and difficult to treat using conventionalanti-infective therapy and re-operation, to surgically excise theinfected site, often becomes necessary. For these reasons, commerciallyavailable bone waxes do not enjoy widespread orthopedic use.

Other products or techniques used in this application include oxidizedcellulose products indicated for soft tissue hemostasis, e.g.,Surgicel®, which are absorbable and would not be expected to induce thecomplications cited above for bone wax. However, they are not effectivehemostatic products for bone because of their inappropriate physicalform (knitted fabric) and are too difficult to use effectively on cutbone because of lack of adherence within the bone pores.

The use of electrocautery, which thermally sears oozing blood vesselsclosed, is time-consuming and produces widespread tissue damage whichmay delay osteogenesis as well as allow soft tissue in-growth thatinterferes with normal bone union, presenting difficult problems fororthopedic surgeons in general and spine surgeons in particular.

Collagen in various forms, alone or in combination with fibrin andsuspended in various delivery vehicles, has been proposed as a bonehemostatic agent but problems with, for example, storage stability,cohesiveness, and biocompatibility have prevented practical fruition.

The adaptation of synthetic absorbable polymers to this application hasnot succeeded, apparently because of technical difficulties in suitablyformulating hydrolytically unstable synthetic absorbable polymers intopractical products with reasonable package shelf life, useful handlingproperties and acceptable biocompatibility and absorption rates.

The second body of prior art primarily is concerned with bone healingand the treatment of bone defects. The bone healing prior artcompilation primarily describes the development of biocompatible,absorbable vehicles to deliver and support processed particulateallogeneic bone as it is applied to defects such as excised cavities.These liquid or paste-like vehicles consist of a variety of polyhydroxycompounds, ester derivatives of polyols, hydrogels, and the like,sometimes containing additives to increase the viscosity of the vehicle(to retard dissipation of the vehicle and, thereby, extend thecohesiveness of the implanted mass) or factors to induce new bonegrowth. Anti-infective, anti-tumor and other additives also aredescribed for these products. In no instances are these compositionsindicated for, act as, or described in the art and claimed as bonehemostatic agents.

Thus, there remains a need in the art for a body absorbable hemostaticimplant material that has suitable handling properties, biocompatibilityand body absorption rates.

BRIEF SUMMARY OF THE INVENTION

The invention provides a composition having a waxy or putty-likeconsistency that preferably is capable of adhering to bone andfunctioning as an absorbable bone hemostatic agent. The compositioncomprises solid poloxamer having an average molecular weight of about7,000 g/mol to about 15,000 g/mol, dextran having a molecular weight ofabout 40,000 Daltons to about 2,000,000 Daltons, optionally a fatty acidsalt, and water.

Preferably the composition of the invention comprises (a) about 10% toabout 75% (e.g., about 10% to about 65%), by weight of the composition,solid poloxamer having the molecular formulaHO(C₂H₄O)_(a)(C₃H₆O)_(b)(C₂H₄O)_(a)H having an average molecular weightof about 7,000 g/mol to about 15,000 g/mol, wherein the weight percentof ethylene oxide is 70 wt. % or more, based on the weight of thepoloxamer, (b) about 1% to about 50%, by weight of the composition,dextran having a molecular weight of about 40,000 Daltons to about2,000,000 Daltons; (c) about 10% to about 50%, by weight of thecomposition, water, and (d) about 0% to about 25%, by weight of thecomposition, finely powdered fatty acid salt. The amounts of (a)-(d) andany optional components that may be present desirably are sufficient toform a putty-like or wax-like consistency at ambient temperature.

The invention also provides a package comprising the composition of theinvention, wherein the composition is amorphous or in a generallyrounded form or in a generally parallelepiped form, wherein saidcomposition is sealed in an aseptic barrier package, and is sterile orsterilizable.

The invention further provides a method for mechanically controlling thebleeding of bone which comprises applying an effective amount of thecomposition of the invention to the affected area.

DETAILED DESCRIPTION OF THE INVENTION

The composition of the present invention comprises a solid poloxamer, ahigh molecular weight dextran, water, and optionally a fatty acid salt.The composition of the present invention can have any suitable viscosityand cohesive strength and can have a waxy, or putty, or non-puttyconsistency. In many embodiments the composition of the invention has aputty-like consistency at ambient temperature. In one embodiment, thecomposition of the invention is a mechanically hemostatic tamponadeuseful in stopping the bleeding of bone by the application of theputty-like composition to the affected area. By “mechanically hemostatictamponade” is meant that the composition functions by mechanicallycompressing the bleeding areas of the bone to arrest hemorrhaging asopposed to functioning by chemically hemostatic means, i.e., thearresting of hemorrhaging, in whole or in part, using a chemical means.In another embodiment, the composition of the invention, in addition tobeing mechanically hemostatic, is also osteogenic in that they containan added ingredient, i.e., a bone growth-inducing material, to aid inthe induction of bone growth.

The term “putty” is used herein as it is used in the art and isgenerally known to the skilled artisan. Dough (such as pastry dough),modeling clay, and glazier's putty of varying viscosities, depending onthe indications and ultimate use, are examples of the consistency of asuitable product. Putties of various viscosities useable in theinvention include those that are capable of adhering to bone. Ingeneral, putties which are soft, moldable, preferably non-elastic,cohesive mixtures prepared from a finely powdered substance intimatelyadmixed with a liquid dispersing vehicle and having a shape which iscapable of being deformed in any direction, are suitable consistenciesfor the putty-like compositions of the invention. As will be describedlater, however, compositions which have lower cohesive strengths thanthe putties described above, are within the scope of the invention, andmay be used in specific applications in which the more viscous, highercohesive strength putties are less suitable. For purposes of thisinvention, a major difference between putties of the invention andmaterials not considered to be putties (i.e. non-putties), but which arestill within the scope of the invention, is that the non-putties havelower cohesive strengths than the cohesive strengths of the puttyformulations. Individual non-putties of the invention are characterizedby having the cohesive strength of creams, pastes, ointments, lotions,foams, gels, whipped egg whites, whipped cream, and the like.Preferably, the non-putties have only a fraction of the cohesivestrength of putties of the invention, tending to be easily collapsibleor easily torn apart under small stresses that would not, generallyspeaking, have the same effect on putties. The description which followsis given mainly in the context of the putties of the invention, it beingunderstood, however, that if less cohesive strength materials aredesired, the skilled artisan will simply make the appropriate changes inthe proportions of components or add other substances to achieve thesame purpose.

The poloxamer can be any suitable solid poloxamer. A poloxamer is anonionic triblock copolymer containing a central hydrophobic chain ofpolyoxypropylene (i.e., poly(propylene oxide)) flanked by twohydrophilic chains of polyoxyethylene (i.e., poly(ethylene oxide)). Theproperties of the poloxamer are modified by customizing the lengths ofthe polymer blocks. Typically, the poloxamer used in the composition ofthe invention has an average molecular weight of about 7,000 g/mol toabout 15,000 g/mol, preferably about 9,000 g/mol to about 13,000 g/mol,wherein the weight percent of ethylene oxide is 70 wt. % or more, basedon the weight of the poloxamer. Desirably the solid poloxamer has themolecular formula HO(C₂H₄O)_(a)(C₃H₆O)_(b)(C₂H₄O)_(a)H, wherein a is 60or greater and b is 25 or greater. Preferably, the solid poloxamer isselected from the group consisting of poloxamer 407 (a=101, b=56),poloxamer 338 (a=141, b=44), and poloxamer 188 (a=80, b=27). The amountof solid poloxamer can be any suitable amount, preferably about 10% toabout 75%, or more preferably about 15% to about 65%, by weight of thecomposition.

The dextran can be any suitable dextran. Dextran is a branchedpolysaccharide comprising a plurality of glucose molecules, wherein thestraight chain comprises α-1,6-glycosidic linkages between glucosemolecules, and the branch chains begin from α-1,3-linkages of theglucose molecules. Typically the dextran is a high molecular weightdextran, e.g., dextran having a molecular weight of about 40,000 Daltonsto about 2,000,000 Daltons. Preferably the dextran has a molecularweight of about 200,000 Daltons to about 1,000,000 Daltons, morepreferably about 400,000 Daltons to about 600,000 Daltons (e.g., 500,000Daltons). The amount of dextran can be any suitable amount. Typically,the composition of the invention comprises about 1% to about 50%, byweight of the composition, dextran. Preferably the composition of theinvention comprises about 5% to about 40%. In some embodiments, it isdesirable to include a relatively higher amount of poloxamer, forexample about 40% to about 75%, in combination with a relatively loweramount of dextran, for example about 1% to about 20% (e.g., about 2% toabout 15%).

The fatty acid salt is a salt of one or more saturated or unsaturatedcarboxylic acids containing about 6 to 22 carbon atoms in the chain,preferably 8 to 20 carbon atoms. More preferably, the fatty acid salt isa salt of a carboxylic acid containing 16-18 carbons in the chain. Thesalts can be any suitable salts, including calcium, magnesium, zinc,aluminum, lithium, and barium salts. Preferably, the fatty acid isselected from the group consisting of caprylic acid, capric acid, lauricacid, myristic acid, palmitic acid, stearic acid, arachidic acid, oleicacid, linoleic acid, and combinations thereof. More preferably, thefatty acid is selected from lauric, myristic, palmitic and stearicacids, with stearic being most preferred. In particularly preferredembodiments, the fatty acid salt is calcium palmitate, aluminumpalmitate, calcium stearate, and aluminum stearate, or aluminum laurate,with calcium stearate being particularly preferred. Desirably the fattyacid salt is a finely divided material having an average particle sizeof 50 microns or less. Preferably the average particle size is betweenabout 3 microns and 25 microns, more preferably between about 6 micronsand 15 microns.

The composition of the invention optionally further comprises a calciumphosphate material, typically in the form of calcium phosphate ceramicgranules. Suitable calcium phosphate materials include hydroxyapatite,tricalcium phosphate (e.g., α-TCP or β-TCP), tetracalcium phosphate,dicalcium phosphate, e.g., monetite and brushite, amorphous calciumphosphate, bioactive glasses composed of SiO₂, Na₂O, CaO and P₂O₅, suchas those composed of 35-60 mol. % SiO₂, 10-50 mol. % CaO, and 5-40 mol.% Na₂O; <35 mol. % SiO₂; >50 mol. % SiO₂, <10 mol. % CaO, and <35 mol. %Na₂; or >65 mol. % SiO₂, and wherein some CaO is optionally replacedwith MgO or CaF₂, some Na₂O is optionally replaced with K₂O, and/or someB₂O₃ or Al₂O₃ is optionally added, bioactive glass ceramics (e.g.,apatite-wollastonite, and the like), carbonated apatites,ion-substituted calcium phosphates (e.g., calcium phosphate material inwhich the phosphate groups are selectively replaced with silicate orcarbonate ions), cation-doped calcium phosphates (e.g., calciumphosphates or calcium carbonate phosphates doped with magnesium, zinc,yttrium, silver, strontium, etc.), and combinations thereof.

Desirably the calcium phosphate material is a finely divided materialhaving an average particle size of 50 microns or less. Preferably theaverage particle size is between about 3 microns and 25 microns, morepreferably between about 6 microns and 15 microns. The amount of calciumphosphate material can be any suitable amount. Preferably, when used,the amount of calcium phosphate material is about 1% to about 40%, orabout 5% to about 25%, based on the weight of the composition.

In other embodiments, the invention optionally further comprises calciumsulfate (e.g., biphasic calcium sulfate) in an amount of about 5% toabout 25%, based on the weight of the composition.

The composition of the invention comprises water or an aqueous solution.The presence of water aids in a variety of ways among which is changingthe tactile quality of the composition. Suitable aqueous vehiclesinclude water, saline, buffer solutions, body fluids (e.g., blood,serum, blood component concentrates), and the like. Desirably, thecomposition comprises a buffer solution that is isotonic and non-toxicsuch that it is suitable for use in medical applications. Typically thebuffer solution has a pH between about 6.5 and 8.5, typically between 7and 8 (e.g., 7.2 or 7.4). A preferred buffer solution for use in thecomposition of the invention is phosphate buffered saline, althoughborate buffered saline and tris buffered saline also can be used.Preferably the buffer solution comprises a chloride salt in combinationwith a phosphate, e.g., sodium chloride in combination with sodiumphosphate, or potassium chloride in combination with potassiumphosphate. Calcium or magnesium salts also can be used. One commonlyused phosphate buffered saline is Dulbecco's phosphate buffered saline.The amount of the water or aqueous solution (e.g., buffer solution) canbe any suitable amount. Preferably the composition of the inventioncomprises about 10% to about 50% water or aqueous solution, orpreferably about 10% to about 50% phosphate buffered saline, based onthe weight of the composition.

Optionally, the composition of the invention further comprises anadditional ingredient selected from the group consisting of anabsorbable colorant, an absorbable anti-infective agent, an absorbableblood clot-inducing agent, an absorbable anti-neoplastic agent, anabsorbable analgesic, and an absorbable radiopaque agent. The colorantcan be any suitable colorant. Suitable colorants include gentian violet,D&C Violet #2, and D&C Green #6. The anti-infective agent can be anysuitable anti-infective agent. Suitable anti-infective agents includetetracycline, vancomycin, cephalosporins, aminoglycosides such astobramycin and gentamicin, silver and its ionic forms, and antimicrobialpeptides. The blood clot-inducing agent can be any suitable bloodclot-inducing agent. Suitable blood-clot inducing agents includeepinephrine, tannic acid, ferrous sulfate, and the double sulfates of atrivalent metal and a univalent metal such as potassium aluminum sulfateand ammonium aluminum sulfate. The anti-neoplastic agent can be anysuitable anti-neoplastic agent. Suitable anti-neoplastic agents includemethotrexate, cis-platinum, doxorubicin, radionuclides such as Strontium89 and the like, and combinations thereof. The analgesic agent can beany suitable analgesic agent. Suitable analgesics include benzocaine,bupivacaine, dibucaine, lidocaine, mepivacaine, prilocaine, procaine,chloroprocaine, etidocaine, tetracaine, xylocaine, propivacaine, NSAIDssuch as ibuprofen and aspirin and the COX-2 specific inhibitors such asrofecoxib and celecoxib, and combinations thereof. The radiopaque agentcan be any suitable radiopaque agent. Typically the radiopaque agent isselected from the group consisting of iodo compounds, e.g., ethylmonoiodo state (Ethiodol, Savage Laboratories), and barium salts such asbarium stearate.

The components described above, when added together in suitableproportions, yield useful, putty-like and non-putty like agents having,to varying degrees, many favorable characteristics. Various combinationsof the components may require different times and temperatures in thepreparation process in order for the putty-like characteristics todevelop. For example, some materials such as finely dividedhydroxyapatite may take longer than other components to achieve theputty-like state. Preferred compositions of the invention are asfollows:

Component Composition A Composition B Composition C Solid poloxamer10%-30% 45%-65% 50%-75% (e.g., poloxamer 407) Dextran 30%-50% 10%-15% 1%-15% (e.g., 500 kD) Phosphate buffered 30%-50% 20%-35% 15%-30% salineStearate salt 0%-5% 0%-10%  5%-15% (e.g., calcium stearate) Total 100100 100

In general, the putty-like compositions of the present invention areabsorbable within a reasonable time, usually within 30 days althoughabsorption times may be extended to several months or longer for someapplications. They are moldable and shapeable by hand at ambienttemperatures, handle well in presence of blood, and are washable withsaline. They sometimes are tacky to the touch, but do not stick to anygreat degree to surgical gloves, wet or dry. They can be radiationsterilized when radiation-sensitive material such as DBM or certainantibiotics are not present.

The actual proportions of the materials selected will vary dependingupon the materials themselves, the number of components used, and theuse desired for the final putty composition. The user will be guidedinitially by the requirement for the desired viscosity, cohesivestrength, and consistency to be obtained, i.e., compositions rangingfrom flowable liquid consistencies to consistencies of creams, pastes,ointments, gels, and the like to the more cohesive putty-likeconsistencies, while maintaining other characteristics desired in theultimate use of the component.

The compositions described in this specification, when used surgically,must be sterile. All, except those noted below, are radiationsterilizable, using, for example, a standard cobalt-60 radiation sourceand a nominal dose of 25 kGy. Exceptions are formulations containingradiation-sensitive additives such as demineralized bone matrix, bonemorphogenic protein, certain antibiotics, unsaturated molecules such asoleic acid and the like. When such materials are used, sterility may beachieved by radiation-sterilizing the bulk putty-like material andaseptically adding the sterile radiation-sensitive additive followed byaseptic packaging or by using e-beam or gamma radiation under controlledtemperatures. The compositions of the invention can also optionallyfurther comprise tocopherol acetate or radioprotectant agents which aidin preserving the biological activity during the sterilization process.

The composition of the invention may be sterile or sterilizable and maybe packaged in several formats. The packages themselves may be sterileor sterilizable. The compositions may be packaged as an amorphous (i.e.,shapeless or having no definite shape) material such as a paste, cream,or putty, or in the shape of its container. They may be shaped generallyas a parallelepiped or as a generally rounded form, examples of theformer being small brick-shapes or slabs (in the shape of a stick ofchewing gum), and examples of the latter being cylindrical-shaped,egg-shaped, or spherical-shaped products. Alternatively, when theapplication permits and the viscosity is suitable, the product can bepackaged in a syringe-like or plunger-assisted dispenser expressable orextrudable through an orifice of appropriate cross section and shape,for example, for use in minimally invasive percutaneous spinaltechniques. A mechanical assist device similar to that used for caulkingmay be included. Another package contains the product in a squeezable,deformable tube such as a toothpaste-type tube or a collapsible tubesuch as those used in caulking applications, with an orifice shaped andsized to dispense any suitable shape onto the surface to be treated. Thepackage may comprise an outer barrier as an overwrap, for example, apeelable blister pouch, to allow aseptic delivery of the package to thesterile field.

While the foregoing discussion has been presented largely in the contextof materials having the consistency of a putty, in some applications itmay be desired to have a relatively less viscous or less cohesivecomposition. For example, it may be desired to place the composition ofthe invention into a void in the bone (drilled or otherwise formed, e.g.hairline fractures) into which a putty of high viscosity can be appliedonly with difficulty. A less viscous form of the putty compositions ofthe invention would be a desirable alternative. All one needs to do ismodify the proportions presented herein to allow for a higher liquidconcentration or add a compatible liquid diluent to achieve thispurpose. Using this approach, an injectable form of the material can beobtained as well. Other less cohesive strength, non-putty compositions,such as creams, ointments, gels, lotions, and the like previouslyreferred to, may be prepared in the same manner. In other embodiments,it may be desired that the composition be prepared as a finely dividedpowder or powder aggregate that can be sprinkled in dry form onto ableeding site to form a cohesive past upon contact with surgical fluids.

The present invention also contemplates methods of use of thecompositions of the invention. For example, one embodiment is the methodof mechanically controlling the bleeding of bone by the application ofan effective amount of any of the compositions of the invention tobleeding bone, wherein the composition has a sufficiently denseconsistency, such as in the putty compositions of the invention. In sucha case, the composition is a mechanical hemostatic tamponade.

Another embodiment of the method of use of the invention is the methodof chemically controlling the bleeding of bone by the application of aneffective amount of any of the compositions of the invention, whereinthe composition contains a blood clot-inducing agent as heretofore setforth. In the case of putties, the composition is a chemical hemostatictamponade. Mechanical hemostatic tamponades of the invention which alsocomprise a clot-inducing agent will act as both a mechanical hemostatand a chemical hemostat.

Another method of the invention is the method for inducing the growth ofbone in a bone defect by applying an effective amount of any compositionof the invention containing a bone growth-inducing agent, to theaffected area of bone, especially when the composition includes a bonegrowth-inducing material such as a calcium phosphate material.

Another method is the method for treating an infection in or around abone by applying an effective amount of any composition of the inventioncontaining an anti-infective agent, to the affected area of bone to betreated.

Another method is the method for destroying cancer cells in or around abone by applying an effective amount of any composition of the inventioncontaining an anti-neoplastic agent, to the affected area of bone whichcontains such cells.

Another method is the method for reducing pain from an area in or arounda bone by applying an effective amount of any composition of theinvention containing an analgesic agent, to the affected area.

Another method is the method for controlling inflammation in or around abone by applying an effective amount of any composition of the inventioncontaining an anti-inflammatory agent, to the affected area.

Another method is the method for assessing the status of an area in boneto which an implant has been applied by applying an effective amount ofany composition of the invention containing a radiopaque agent, to theaffected area and thereafter radiographically visualizing the area andmaking a determination of the status of the area.

The following examples further illustrate the invention but, of course,should not be construed as in any way limiting its scope.

Example 1

In this example and in all subsequent examples, unless otherwiseindicated, the compositions were prepared by mechanical blending of alldry ingredients first and thereafter adding gradually any liquidcomponents.

Component Composition A Composition B Composition C Poloxamer 407 20% 55% 60.83% Dextran 500 kD 40% 12.5%  6.75% Dulbecco's 40% 27.5% 23.75%phosphate buffered saline Calcium stearate  0%  5%  9.17%

The compositions were “worked” with a spatula at room temperature untilthe desired consistency was obtained. The compositions of the inventionA, B and C yielded a putty-like mass.

Example 2

The in vivo response to each of the hemostatic compositions A-C of theinvention described in Example 1 was evaluated in a cancellous defect inyoung (10 week old) rabbits at 5 and 14 days postoperatively.

Three animals per time point (6 sites) were implanted with one each ofrespective Compositions A-C with contralateral control of a clinicallyavailable water soluble bone hemostat predicate (Ostene, Apatech Ltd.,Baxter Healthcare Corp.). One animal per time point (2 sites) was usedfor sham surgery (empty) for inflammatory comparison.

A 3×10 mm drill hole defect was created in the left and right distalfemurs of 8 New Zealand White Rabbits. Compositions (i.e., CompositionsA, B, C, Ostene, or none (empty) according to the table below) werecarefully placed in the defect to the height of the original cortex andthe skin was closed using 3-0 Polysorb. The rabbits were givenpost-operative analgesia and returned to their cages where they werefree to mobilize and weight-bear immediately post-operatively astolerated. The rabbits were monitored daily following surgery.

Rabbit Left Femur Right Femur Time Point 1 Composition A Ostene 14 days2 Ostene Composition B 14 days 3 Composition C Ostene 14 days 4 EmptyOstene 14 days 5 Composition A Ostene  5 days 6 Ostene Composition B  5days 7 Composition C Ostene  5 days 8 Empty Ostene  5 days

Each of the Compositions A-C handled well and was easily placed into thedefect. Hemostasis was achieved immediately upon filling the defectswith each of the Compositions A-C, while the empty sham control sitesbled for some time after defect creation and hemostasis was achievedonly after 3-4 minutes with a sponge.

No post-operative complications were encountered and no adversereactions were noted in any animal at any time point. Faxitronradiographs in the anteroposterior and lateral planes taken at 5 and 14days post-operatively revealed no abnormal bone reactions or bonyresorption of post-operative fractures. Micro computed tomographyconfirmed the radiographic findings in terms of site placement and noevidence of adverse inflammatory response in any animal at 5 or 14 days.Bone healing was not evident in any animal at 5 days, but progressed ineach animal with time by 14 days. No abnormalities were noted on thedistant organs (heart, liver, kidney, spleen, and lungs) when examinedmacroscopically or microscopically at the time of harvest (5 or 14 dayspost-operatively).

Histology of the soft tissue overlying the defect at 5 days revealed thepresence of normal inflammatory and granuloma reactions in all sitesincluding those from the empty defect. The granuloma reactions wereconsistently the surgically created defect. Histology of the soft tissueoverlying the defect at 14 days revealed no major differences forCompositions A-C compared to the predicate (Ostene).

At day 5 postoperatively, the bone defects were filled with soft tissuesand haematoma surrounding the implanted materials. The cell populationincluded red blood cells, white blood cells, fibroblasts, monocytes,macrophages, giant cells, osteoblasts, osteoblast progenitors andosteoclasts. The soft tissues penetrated into the implant materials withnew blood vessel formation in the bone defect site. Compositions A-Cpresented similar features in terms of cellular population. CompositionsB and C had a similar response while Composition A appeared to have alower overall cellular infiltration. The cell population and amount offibrous tissue was similar to the predicate material (Ostene). The emptydefect showed a similar cell population as Compositions A-C and thepredicate (Ostene) but with fewer white blood cells and less granulomareaction.

At day 14 postoperatively, the predicate (Ostene) treated defects hadfibrous soft tissues as well as some new woven bone. The soft tissuecomponent included fibroblasts, monocytes, white blood cells(neutrophils and lymphocytes), and some macrophages and giant cellspresent. The defects filled with Compositions A-C had a similar responseto the predicate (Ostene) in terms of new woven bone as well as thepresence of fibrous tissue and cellular components. The histology of theempty defect at day 14 revealed the presence of new woven bone.

The amount of new bone in the defects and other tissue was evaluated byhistomorphometry (see table below). Residual material was not able to bedifferentiated at 5 days and could not be found at 14 days, reflectingin part the in vivo resorption of the material as well as the histologyprocessing fluids that could potentially remove remaining material.

Rabbit Composition Time Point New Bone Other Tissue 1-left Composition A14 days 0.12 0.88 1-right Ostene 14 days 0.16 0.84 2-left Ostene 14 days0.41 0.59 2-right Composition B 14 days 0.20 0.80 3-left Composition C14 days 0.33 0.67 3-right Ostene 14 days 0.16 0.84 4-left Empty 14 days0.39 0.61 4-right Ostene 14 days 0.51 0.49 5-left Composition A  5 days0.00 1.00 5-right Ostene  5 days 0.16 0.84 6-left Ostene  5 days 0.030.97 6-right Composition B  5 days 0.00 1.00 7-left Composition C  5days 0.00 1.00 7-right Ostene  5 days 0.03 0.97 8-left Empty  5 days0.27 0.73 8-right Ostene  5 days 0.00 1.00

Each of the compositions A, B and C of the invention demonstrated anacceptable inflammatory response and no bony reactions relative to anempty defect and a predicate material (Ostene). This exampledemonstrates that each of the compositions A-C of the invention have anacceptable in vivo response.

Example 3

The hemostatic properties of each of the hemostatic compositions A-C ofthe invention described in Example 1 was evaluated in cortical defectslocated on the ribs of a pig.

The ribs of a pig were exposed and 1.5 cm×1.5 cm cortical bone defectswere created using a 4 mm burr attached to a nitrogen powered handpiece.Cortical bone was removed from the defect site until widespreadpunctuate bleeding to brisk oozing was observed. Once bleeding wasobserved, Compositions A, B, and C were applied to the defects untilhemostasis was achieved. The compositions were removed from thepackaging and then manipulated with dry gloves to warm the material tomake it soft and malleable. Once the desired consistency was reached,the softened articles were pressed into the bleeding bone defect siteusing a finger and the defect was filled. The application wasaccomplished by either pressing the compositions into the defect site orsmearing the compositions into the defect site.

Once hemostasis was determined to be adequate after application,observations for bleeding were performed at 5 and 10 minutes. After 10minutes, the sites were observed every 30 minutes until compositionfailure or 6 hours after the initial defect. A similar defect wascreated initially and at the end of the procedure to act as a control.The control defect was observed at 5 and 10 minutes for bleeding, and at10 minutes, bone wax (Ethicon) was applied to create hemostasis. Asummary of the defect locations and treatment is provided in the tablebelow.

Anatomical Location (cranial to Dorsal Middle Ventral Rib caudal) RibDefect Rib Detect Rib Defect 1 4 Untreated Control Composition AComposition B 2 5 Composition C Composition B Composition A 3 6Composition A Composition C Composition B 4 7 Composition B CompositionA Composition C 5 8 Composition C Untreated None Control

Composition A was superior for application using the “press on”technique, while Compositions B and C were difficult to conform to thedefect. The press on technique created considerable excess composition,which made evaluation of rebleeding difficult. A summary of the resultsusing the press on technique are summarized below.

Composition A A B B C Time to achieve hemostasis (seconds) 7 23 25 28 60Rib Number 1 3 1 3 3 Time of rebleed (h) 5 min 1 2 0.5 0.5

Compositions B and C were best in terms of the “smear” technique, whileComposition A was the worst for application with slippery properties andsticking of the composition to gloves during application. All of theCompositions A, B and C applied with the smear technique maintainedhemostasis for greater than 1 hour. A summary of the results using thesmear technique are summarized below.

Composition A A B B C C Time to achieve hemo- 5 22 10 20 57 11 stasis(seconds) Rib Number 2 4 2 4 2 4 Time of rebleed 2 2 5 3.5 Not observed1.5 (h) (6 h)

This example demonstrates that all of the compositions A-C of theinvention have suitable hemostatic properties. Composition A wassuperior for application using the “press on” technique, whileCompositions B and C were superior for the “smear” technique. All ofCompositions A-C applied with the smear technique maintained hemostasisfor at least 1 hour.

All references, including publications, patent applications, andpatents, cited herein are hereby incorporated by reference to the sameextent as if each reference were individually and specifically indicatedto be incorporated by reference and were set forth in its entiretyherein.

The use of the terms “a” and “an” and “the” and “at least one” andsimilar referents in the context of describing the invention (especiallyin the context of the following claims) are to be construed to coverboth the singular and the plural, unless otherwise indicated herein orclearly contradicted by context. The use of the term “at least one”followed by a list of one or more items (for example, “at least one of Aand B”) is to be construed to mean one item selected from the listeditems (A or B) or any combination of two or more of the listed items (Aand B), unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to,”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe invention.

Preferred embodiments of this invention are described herein, includingthe best mode known to the inventors for carrying out the invention.Variations of those preferred embodiments may become apparent to thoseof ordinary skill in the art upon reading the foregoing description. Theinventors expect skilled artisans to employ such variations asappropriate, and the inventors intend for the invention to be practicedotherwise than as specifically described herein. Accordingly, thisinvention includes all modifications and equivalents of the subjectmatter recited in the claims appended hereto as permitted by applicablelaw. Moreover, any combination of the above-described elements in allpossible variations thereof is encompassed by the invention unlessotherwise indicated herein or otherwise clearly contradicted by context.

The invention claimed is:
 1. A putty composition consisting of: (a)about 55%, by weight of the composition, poloxamer 407; (b) about 12.5%,by weight of the composition, dextran having a molecular weight of about500,000 Daltons; (c) about 27.5%, by weight of the composition,phosphate buffered saline, and (d) about 5%, by weight of thecomposition, calcium stearate, wherein the putty composition is moldableat ambient temperature and non-elastic.
 2. A putty compositionconsisting of: (a) about 60.83%, by weight of the composition, poloxamer407; (b) about 6.25%, by weight of the composition, dextran having amolecular weight of about 500,000 Daltons; (c) about 23.75%, by weightof the composition, phosphate buffered saline, and (d) about 9.17%, byweight of the composition, calcium stearate, wherein the puttycomposition is moldable at ambient temperature and non-elastic.